Tom;

Penetrating oils may help, but you MUST start out by using one of the approved pullers on this stretched joint, which applies concentric tension between lugs and axle...applying force non-concentrically or anywhere else (like edge of drum)...like so:

...will either not work, and/or break or damage things...once the proper puller is attached and putting the joint under mega-tension, some heat on the hub will help as it "grows" the hub a little, and maybe just enough to pop it apart...all this pain and suffering can be avoided by using the slightest film of graphite grease during last assembly...just saying...

See: http://sw-em.com/Brake_Drum_Notes.htm

Cheers